Okay, I have a 315G tank filtered by a sump that is around 100G. The sump is fead by 2 overflow boxes that turn the tank over about 6 times per hour. With all of the water flowing through the sump/wetdry, do I need the return spraybars to aggitate the water surface or do I have sufficent gas exchange taking place within the sump? I really prefer the return lines spraying deeper in the tank.
